Background
Malignant melanoma is a skin cancer of which the incidence is said to be raising in recent years. Prevention may result in decrease of the incidence. Early detection may result in the detection of earlier stages of the disease. In Limburg a combined campaign of prevention and screening has been performed in recent years and its effects should be evaluated.
Objectives
To study time trends of malignant melanoma incidence and the evolution of stages of detected melanomas and to relate them to interventions in previous years.
Methods
An ongoing multi-faceted intervention, including information as well as screening invitations (Euromelanoma project) was implemented in 1999. Time trends of malignant melanoma were studied on the basis of data from the Limburg Cancer Registry (LIKAR) of 1996-2005. Stages were studied on the basis of an additional clinical registration completed by pathologists and dermatologists.
Results
Over the years 1996-2005, the crude incidence rate of malignant melanoma was 6.8/100,000 patient-years in males and 11.6 in females, with a European standardized incidence rate (ESR) of 6.4 in males and 10.5 in females. The incidence progressively increased with age.
In males, the ESR initially decreased, followed by a significant increase from 3.0 in 1998 to 7.6 in 2005. On average this is a yearly increase of 0.5 per 100,000 persons (p= 0.04). In females the curve fluctuates, resulting in almost similar rates in 1996 and 2004 (p = 0.85), but with a sudden increase from 9.2 to 15.8 between 2004 and 2005.
Neither the Breslow nor the Clarck classification showed any significant change over the registration period. The proportion of lymph node invasion, metastasis and ulcerations did not change.
Discussion
With the exception of a small and clinically irrelevant increase in ESR in males, no changes over time were detected in incidence or stage distribution. The effect of the intervention seems limited.